Abstract Phonon velocities and densities for Pt were measured based on inelastic X-ray scattering from ambient pressure to 20 GPa in order to independently determine its equation of state (EOS). Phonon velocities were determined with sine dispersion relations. Cij values were obtained by fitting phonon velocities and densities to the Christoffel equation. We found that the obtained Cijs were in good agreement with previously reported Cijs at ambient condition. Based on the Cij values in various conditions, experimental pressures were calculated. The EOS of Pt as a primary pressure scale was determined based on the experimental pressures. We report K’ = 5.17 with fixed KT = 274.1 GPa and V0 = 60.360 A3 for Vinet EOS. Our scale is in good agreement with several previously published scales based on shock experiments and XRD.

中文翻译：

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基于非弹性 X 射线散射测得的单晶 Pt 的弹性常数高达 20 GPa：对建立状态方程的意义

摘要 基于从环境压力到 20 GPa 的非弹性 X 射线散射测量 Pt 的声子速度和密度，以独立确定其状态方程 (EOS)。声子速度由正弦色散关系确定。Cij 值是通过将声子速度和密度拟合到 Christoffel 方程来获得的。我们发现获得的 Cijs 在环境条件下与先前报道的 Cijs 非常吻合。根据各种条件下的 Cij 值，计算出实验压力。Pt 的 EOS 作为主要压力标度是基于实验压力确定的。对于 Vinet EOS，我们报告 K' = 5.17，固定 KT = 274.1 GPa 和 V0 = 60.360 A3。我们的标度与之前基于冲击实验和 XRD 发布的几个标度非常一致。